Copper oxide rectifier



Oct. 2, 1934. I BOWLING 1,975,356

COPPER OXIDE RECTIFIER Filed Sept. 19, 1953 INVENTOR Philip H.D0wlz'12y.

BY QRFM HIS A TTORNEY Patented Oct. 2, 1934 UNITED STATES PATENT OFFICE COPPER OXIDE RECTIFIER Application September 19, 1933, Serial No. 690,079

1 Claim.

My invention relates to copper oxide rectifiers, and has for an object the provision of a rectifier in which each disk will have as much oxide on its back, and will have such oxide as uniformly distributed, as is consistent with the necessity for making contact to the mother copper by means of the usual lead contacting washer.

I will describe two forms of rectifier units embodying my invention, and will then point out the novel features thereof in a claim.

In the accompanying drawing, Fig. l is a front View showing one form of rectifier unit embodying my invention. Fig. 2 is a sectional view on the line II-II of Fig. 1. Fig. 3 is a view showing a modified form of rectifier unit also embodying my invention. Fig. 4 is a sectional view on the line IVIV of Fig. 3. Fig. 51s a view showing one means of mounting units of the type shown in Figs. 1 and 2 during the oxidizing process. Fig.

6 is a view showing another form of rectifier embodying my invention. Fig. 7 is a sectional view on the line VII-VII of Fig. 6, and Fig. 8 is a sectional view on the line VIIIVIII of Fig. 6.

Similar reference characters refer to similar parts in each of the views.

Referring first to Figs. 1 and 2, the reference character A designates a rectifying unit comprising a copper disk 10 which is bent, either during or after the punching operation, so that its shape is concavo-convex, and which is subsequently oxidized to form a layer of cuprous oxide 11 on the concave surface of the disk. This unit is, of course, provided with the usual hole 3 to receive the bolt on which a plurality of such units will be mounted to form a rectifier assembly.

Referring now to Fig. 5, the reference character 2 designates the usual fork on which the copper disks are .mounted during the oxidizing process. This fork is provided with a notch 4 which receives two of the copper disks, and these disks are mounted in the notch 50 that their convex surfaces are in mutual contact. During the oxidizing process the layer of cuprous oxide of uniform thickness will be formed on the concave surface of each disk of surface A, and superposed on this layer of cuprous oxide will be a layer of cupric oxide. The convex surface of each disk will also have a layer of cuprous oxide, superposed on which is a layer of cupric oxide, but these layers will be relatively thin near the center of each disk and will gradually increase in thickness toward the outer edge of the disk.

After the oxidizing process is completed, each disk will be treated with a suitable agent, such as nitric acid, to remove the cupric oxide from each surface and to also remove the relatively thin layer of cuprous oxide which exists near the center of each disk on its convex surface. It follows that mother copper will be exposed on the convex surface of each disk near its center, and this mother copper will serve for contact between the disk itself and the usual lead contacting Washer which is interposed between the disk and the cuprous oxide surface of the next adjoining disk in the assembled rectifier.

Referring now to Figs. 3 and 4, the disk shown in these views is toroidal in shape instead of concavo-convcx. In Figs. 6, land 8 the disk is in the form of a portion of the surface of a cylinder.

The precise shape of the disk is immaterial, provided that the disk has a gradual curvature.

By bending the disks in accordance with my invention, I am able to provide for a relatively thick and uniform coating of cuprous oxide on the back or concave surface of the finished unit. Such units will suffer relatively small deformation during the carbonization and assembly steps in the production of the rectifier. Furthermore, the uniform coating of oxide on the back of the disk will allow the units to be assembled in stacks with so very little danger of cracking the oxide on the rectifying concave side of the unit. This will result in relatively low average leakage or back current, will tend to eliminate any occasional units having high leakage current, and will in 35 general result in a highly uniform production in so far as leakage current is concerned.

Although I have herein shown and. described only two forms of rectifier units embodying my invention, and have described only one process for the manufacture of such rectifying units, it is understood that various changes and modifications may be made therein within the scope of the appended claim without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is: 1

The process of making rectifier units which consists in providing curved disks of copper, oxidizing said disks while they are mounted in pairs with the convex surfaces of the disks of each pair in contact, and removing the cupric oxide from the entire concaved surface of each disk and. both the cupric oxide and the cuprous oxide from that portion of the convex surface of each disk at and near the place where the disk engaged the other disk of the same pair during the oxidizing process.

PHILIP H. DOWLING. 

